I. Field
The present invention relates generally to electronics, and more specifically to a modulator for use in a communication system.
II. Background
In a communication system, a transmitter may first process data digitally to obtain coded data. The transmitter may generate an inphase (I) modulating signal and a quadrature (Q) modulating signal based on the coded data. The transmitter may then modulate a carrier signal with the I and Q modulating signals to obtain a quadrature modulated signal that may be more suitable for transmission via a communication channel. The carrier signal is typically a periodic signal (e.g., a sinusoidal signal) of a particular frequency. The quadrature modulation varies both the amplitude and phase of the carrier signal with the modulating signals. Information would then reside in the changes in the amplitude and phase of the carrier signal. It is desirable to perform quadrature modulation using a modulator having good performance.